Impact of Coinfection with Schistosoma mansoni on the Antibody Response to Helicobacter pylori.

PURPOSE In many tropical areas, the coinfection of Schistosoma spp. and other pathogens is frequent. The impact of schistosomiasis on other infections has been demonstrated for several organisms. Infection with the widely spread bacterium, Helicobacter pylori, has been linked to ulcers and tumors of the digestive system with the humoral immune response playing possible modulatory roles. The present study investigated the impact of patent S. mansoni infection on the antibody response to H. pylori. METHODS A total of 100 participants from a schistosomiasis endemic area in Egypt were enrolled in the study. Based on the detection of S. mansoni eggs and H. pylori coproantigen in fecal samples, they were equally divided into four groups: schistosomiasis, concomitant S. mansoni and H. pylori infection, H. pylori infection alone, and healthy controls. Anti-H. pylori IgG and IgA were determined in serum samples using ELISA. RESULTS A significantly lower IgA seropositivity rate and significantly lower IgG levels were found in patients with concomitant schistosomiasis (Gp2) compared to those infected only with H. pylori (Gp1). CONCLUSIONS Concomitant S. mansoni infection with light to moderate intensity alters serological responses to H. pylori. In schistosomiasis endemic areas, the routine examination for H. pylori infection should, therefore, rely on coproantigen level rather than antibody levels. Further studies should investigate histopathological changes and other immunological parameters in coinfection.